The MSM (mechanical) process fell out of favor in the 1980s: Pork and beef packers were reluctant to use it, and for the same reason they were reluctant to use irradiation: They feared consumers would regard the product as unsafe.
But the idea was sound --- use those scraps --- so inventors developed other ways to “salvage” scraps without getting bone into the mix. These people, who included a scientist at a Nebraska university, created a second generation of the “separation” process.
Among them was Eldon Roth, who founded BPI, Inc., the company at the center of the current controversy. Roth is a natural engineer: despite lack of formal training, he devised ways to use, process, and preserve meats in innovative ways, and designed the machinery needed to carry out those processes. (*1)
Roth’s method for utilizing scrap meats consisted of subjecting the carcass to very high pressure water bath; the pressure scrubbed the carcass clean of all meat, sinew, etc. without taking any bone with it. Then he ran the scraps through a “desinewing device for the removal of virtually all non-functional material such as cartilage, bone chips, connective tissue, and sinew.” (*2)
Next the material was subjected to “a modified centrifuge” that eliminated most of the fat, leaving muscle (protein) behind. (*3)
The resulting meat matter, which was 94% lean, was flash frozen (a process that takes about 90 seconds), chopped, pressed into a block form, boxed, and shipped to other packers, who incorporated it into their ground beef.
(Roth himself was not a beef processor. He didn’t slaughter animals. Instead, he bought carcasses from other meatpackers and only used those that he deemed to be safe, free of contaminants, and so forth.)
The problem with these second-generation processes was e. coli: The more a carcass is handled, the more likely that some of the bacteria in the carcass will migrate out of the intestines and collect on blades or on parts of the carcass.
What to do? Roth came up with (another) ingenious solution: In its natural state, beef contains ammonia and has a certain pH level. By elevating the pH level, he could kill bacteria. He ran the meat stuffs through a “blender” “where nH3 [was] added to form ammonia hydroxide, which elevate[d]d the pH levels in the finished product.” (*4) (*5)
I gather that Roth needed a fair amount of trial and error to get the level right: enough to kill bacteria, but not so much that the meat smelled like ammonia. (Apparently that was a problem in the early days of this method.) Think of this as the grandchild of the original MSM process.
If you’ve been tracking the current controversy, you know that many people are bothered by the ammonia part of the equation. Bare minimum, most people don’t understand what it is. I gather we can thank Jamie Oliver for that.
During an April 2011 segment of his TV show, he told viewers he wanted to show them what he “imagined” packers did in their plants:
If you don't want to watch, here's a summary: He shoved hunks of beef carcass into a washing machine to demonstrate the “centrifuge” process. Next he dumped “rendered” meats into a container, added liquid ammonia, and then told the audience that’s what packers were doing to the stuff. All the while, he was explaining that the original product was “inedible.” Not safe for humans.
Oy. So far off the mark that it’s not even funny. And, alas, why so many journalists and bloggers keep referring to beef scraps being “dunked” in ammonia. It’s gas, folks. Gas. Not liquid. And many foods, both “natural” and processed, contain ammonia. Eat onions? You’re eating ammonia. Eat cheese? Ditto. Eat grass-fed, “organic” beef? It contains ammonia. So do many PROCESSED foods.
As for Oliver’s claim that PS begins with parts of the animal that are unsafe to eat, well, that’s simply not true.
Also, and for what it’s worth, BPI, Inc. has been lauded for many years for its devotion to sanitation and safety: the conveyors belts, for example, are outfitted with top and bottom sprayers to sanitize the belts constantly. Even the air in the plant is scrubbed and sanitized.
Next: Testing and food safety
*1: For a time line of BPI’s history, see this report by James Andrews in Food Safety News. Andrews’ work is reliable. He’s one of the few “food” reporters out there who focuses on facts rather than innuendo.
*2: Brent Langman, “Creating Food Safety Through Innovation,” National Provisioner 216, no. 4 (2002): 26.